In message , David
Lang writes

"Chris Bacon" wrote in message

Get some brick cleaner from Jewsons, which is dilute
hydrochloric acid (check the label). Bale out the
pan, top up with the cleaner, leave for a few hours,
flush repeatedly, repeat if you need to. Don't try &
chisel the scale off, or you may damage the glaze.

No don't !!!!! Strong Hydrochloric acid can damage the glaze! I know, I've
done it!

Same here - if you remove the glaze it goes porous and you end up with a
much bigger problem


--
geoff